Rayhaan JaufeerallyandClaude Fable 5.1
1fc44798b7
New crate bgp-fib. It follows the routing table's best routes and keeps
the kernel's routing table the same, and learns the machine's interfaces
and addresses from the kernel, which is what says whether a next hop can
be reached.
- netlink: the rtnetlink messages used (routes, addresses, links, errors),
as bytes and back. No I/O; property tested and fuzzed.
- interfaces: what is directly reachable, and from which interface.
- plan: what to ask the kernel for, given the best routes and what the
kernel has. No I/O; tested against a model kernel.
- kernel (Linux only): the sockets and the task. Requests go in batches;
routes of ours found at startup are kept if still right and removed if
not; a change of interfaces has every route worked out again; a clean
stop removes our routes.
Only routes marked proto bgp with the configured table and metric are
ever touched. A best route is installed if its next hop is a neighbor;
next hops further away are not resolved through other routes yet, and
such prefixes are counted and shown instead.
Configured with `kernel { table metric }`; off by default. The daemon
needs CAP_NET_ADMIN and stops if the kernel refuses it. On shutdown it
closes sessions and then removes its routes.
/api/kernel and the status page show installed, unresolved and refused
counts, the last error and the interfaces; five bgp_kernel_* metrics.
Testing: scripts/kernel-tests.sh runs, in network namespaces of their
own and with only the capabilities the daemon needs, the installer
against `ip route`, the daemon with a peer, and two daemons that route
for each other with pings across over IPv4 and IPv6.
scripts/linux-vm.sh runs that, or anything else, in a Lima VM from
macOS. CI runs the kernel tests and fuzzes the netlink decoder.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
BGP
The bgp crate is an implementation of the Border Gateway Protocol, which is used to exchange routing and control plane information between Autonomous Systems.
The aim of this project is to provide a modern, high performance, secure, programmatic and customizable software package that can be useful to network operators, researchers, and people interested in Internet.
Current status.
The project is currently being rewritten from scratch to be more modular and maintainable, as well as to fix deeper issues with the previous implementation.
⚠️ Warning: This is currently a work in progress and not ready for use.
🛣️ Roadmap to v1.0
We aim for the 1.0 release to be functional and stable to operate peering sessions, and to install routes in the Linux Kernel.
- ☐ Implement basic parsers for the fundamental types required
- ✅ Path Attributes from RFC4271
- ✅ Open message
- ✅ Capabilities from RFC4271
- ✅ Update message
- ☐ Notification message
- ✅ Implement scaffolding required to start and configure a server
- ✅ Implement connection logic to establish sessions with peers (passive and active)
- ✅ Routes originated from the configuration, with communities, announced to all peers
- ✅ Read-only HTTP API, status page and Prometheus metrics
- ☐ Implement an efficient data structure for storing prefixes (e.g. Poptrie)
- ☐ Filtering for peer RIB in / out
- ☐ Main / auxiliary RIBs for exchanging routes between peers
Development
CI runs these three on every push, and fails on any warning:
cargo fmt --all -- --check
cargo clippy --workspace --all-targets -- -D warnings
cargo test --workspace
Lints are configured once, under [workspace.lints] in the root Cargo.toml.
unsafe code is forbidden throughout.
cargo test includes property tests: generated messages must survive being
written and read back, and no input, however damaged, may make a parser
panic. They take about a second; for a longer hunt:
PROPTEST_CASES=1000000 cargo test --release -p bgp-packet --test properties
Coverage-guided fuzz targets for the same parsers are in fuzz/; see
fuzz/README.md. CI runs each of them for a minute.
License
Apache License 2.0; see LICENSE.